The Bills blitzed an astonishingly low 17.5 percent of the time, according to ProFootballFocus.com. Considering the league average was 31.5 percent, the Bills were about as aggressive as a kitten.

That's not the only change we could be seeing from the Bills defense this year. The Bills will focus on defending the pass, and could even employ the nickel defense as their base (as opposed to a 3-4 or 4-3).

It wouldn't be unheard of; the Patriots have been doing business that way for years. The Bills were not awful against the pass last season; they were right around the league average in defensive passer rating (84.4), sack rate (6.3 percent) and yards per pass attempt (6.8).

That being said, they invested so heavily on defense, average can't be considered acceptable.

A heavier emphasis on blitzing and on nickel defensive packages will put more pressure on the defensive linemen to maintain gap integrity against the run, because they will have less help from linebackers at the second level.

Defenses that are geared to stop the pass are in vogue right now, and it appears that's exactly what Mike Pettine intends to bring to the Bills.